1. Field of the Invention
This invention relates to a punching system used in combination with an image formation system such as an electrophotographic copier or a printer for automatically making holes in a sheet material of recording paper, etc., to or on which an image is copied or recorded.
2. Description of the Related Art
Hitherto, punching systems used in combination with an image formation system such as an electrophotographic copier or a printer have already been proposed as disclosed in Japanese Patent Laid-Open No. Hei 3-92299, Hei 5-162919, etc., for example. An image formation system according to Japanese Patent Laid-Open No. Hei 3-92299 has a punching mechanism comprising a plurality of punches movable with respect to a paper transport passage, the punching edges being placed side by side in a predetermined spacing in a width direction of recording paper, characterized by paper center detection means for detecting the width direction center of paper based on detection information of a width direction end position of paper in the proximity of a punching section of the punching mechanism and alignment means for substantially matching the width direction center of paper with the arrangement center of the punches before punching.
The punching system for once stopping and punching recording paper discharged from an external system in the transport process according to Japanese Patent Laid-Open No. Hei 5-162919 comprises a punching means driving force transmission mechanism and a rotation claw stopper driving force transmission mechanism coupled to an output shaft of a single motor, a first one-way clutch for actuating the punching means driving force transmission mechanism when the output shaft forward rotates, a second one-way clutch for actuating the rotation claw stopper driving force transmission mechanism when the output shaft reversely rotates, punching means being actuated when the punching means driving force transmission mechanism is actuated for punching holes in recording paper on a transport passage, a rotation claw stopper being actuated when the rotation claw stopper driving force transmission mechanism is actuated for rotating between a recording paper stopping position and saving position, a driven discharge roller being loosely engaged on the same axis as the rotation claw stopper on a stopper shaft for pivotally supporting the rotation claw stopper, a driving discharge roller being coupled to the rotation claw stopper driving force transmission mechanism for diving and coming in contact with the driven discharge roller on an outer peripheral surface for rotating the driven discharge roller in conjunction, a clutch being placed between a driving shaft for pivotally supporting the driving discharge roller and the stopper shaft for turning on and off transmission of a driving force from the driving shaft to the stopper shaft, clutch actuation means for turning on and off the clutch, and a control section for controlling the motor and the clutch actuation means.
However, the prior arts involve the following problems: In Japanese Patent Laid-Open Nose. Hei 3-92299 and Hei 5-162919, the punching mechanism and the punch unit are moved in a direction perpendicular to the recording paper transport direction by the alignment means, etc., in response to the width direction size of transported recording paper, whereby holes can always be punched in the substantial center portions of recording paper sheets different in width direction size. However, the paper center detection means for detecting the width direction center of paper based on detection information of a width direction end position of paper in the proximity of the punching section of the punching mechanism and the alignment means for substantially matching the width direction center of paper with the arrangement center of the punches before punching are operatively associated with each other. Thus, for recording paper which need not be punched, the paper center detection means may also detect the width direction center of paper based on detection information of the width direction end position of paper and move the punching mechanism so as to match the width direction center of paper with the arrangement center of the punches before punching; it is feared that electric power of the image formation system may be wasted or that starting the image formation operation may be delayed by the time required for moving the punching mechanism.
The punching mechanism of the punching system basically inserts recording paper between the punches and dies for receiving the punches and inserts the punches into the dies, thereby punching holes in predetermined positions of the recording paper. When the punching mechanism of the punching system is moved in response to the width direction size of the recording paper, if the punching section containing the punches and the die section are moved separately, it is feared that they may be placed out of position and the punches may come in contact with the dies, breaking the punches. Thus, the punching section and die section are mechanically coupled to each other at both end positions of the width direction where transport of recording paper is not disturbed and are moved in one piece.
By the way, in the punching system, if recording paper of a long width direction size which need not be punched is transported after recording paper of a short width direction size is punched, the end of the recording paper of a long width direction size is caught in the coupling part of the punch and die sections, causing a paper jam to occur. To circumvent this problem, if the coupling part of the punch and die sections is widened to a position where the coupling part is not caught in the recording paper of a long width direction size, the punching system is upsized, causing a new problem.
The punching system comprises the punching mechanism moved in response to the width direction size of recording paper. In an image formation system such as a copier to which the punching system is attached, sheets of recording paper varying in width direction position may be transported and punch positions vary from one sheet to another because of the variations in the width direction positions of recording paper. Thus, as described above, the punching system according to Japanese Patent Laid-Open No. Hei 3-92299 detects the width direction center of paper based on detection information of the width direction end position of paper by the paper center detection means and moves the punching mechanism by the alignment means so as to substantially match the width direction center of paper with the arrangement center of the punches before punching, thereby lessening the variations in the punch positions. However, the punching system according to Japanese Patent Laid-Open No. Hei 3-92299 uses a plurality of light emitting parts and light receiving parts placed facing each other for each of sheets different in width direction size as the detection means for detecting the width direction end position of paper, thus the detection means configuration becomes complicated and expensive, resulting in an increase in cost. Since the detection means for detecting the width direction end position of paper has the light emitting parts placed in physically discontinuous relation, the paper end positions that can be detected by the detection means are determined by the positional relationship among the light emitting parts and the paper end cannot be detected for the size between the adjacent light emitting parts or if the paper end can be detected, the detection precision lowers and a hole cannot accurately be punched In the center position of recording paper. Further, the punching system does not take any steps for a sheet skewed with respect to the recording paper transport direction and also involves a problem of worsening the punch position accuracy because of the skewed sheet.
The invention has been made in view of the above circumstances, and therefore a first object of the invention is to provide a punching system that can not only always punch holes in the centers of sheet materials of recording paper, etc., different in size, but also prevent wasting power because a punching mechanism is not moved unnecessarily for recording paper, etc., which need not be punched and prevent start of the image formation operation from being delayed by time required for moving the punching mechanism.
A second object of the invention is to provide a punching system that can prevent recording paper, etc., of a long width direction size from being caught in the coupling part of punch and die sections and a paper jam from occurring without upsizing the punching system.
A third object of the invention is to provide a punching system that can detect a width direction end position of recording paper with good accuracy and punch holes in predetermined positions of recording paper with good accuracy even if simple means is used as means for sensing a width direction end position of recording paper.
A fourth object of the invention is to provide a punching system that can prevent skew from causing punch hole position accuracy to be worsened if recording paper is skewed.
According to a first aspect of the invention, there is provided, in a punching system for punching holes in a transported sheet material comprising a punching mechanism having a plurality of punching edges disposed on a transport passage of the sheet material in a predetermined spacing in a direction orthogonal to a transport direction of the sheet material for making the punches appear on or disappear from the transport passage, thereby punching a plurality of holes in the sheet material in the predetermined spacing along a width direction of the sheet material and means for moving the punching mechanism in the direction orthogonal to the transport direction of the sheet material, the improvement wherein the punching mechanism has a plurality of predetermined standby positions where the punching mechanism is previously moved by the move means and stands by based on size information in the width direction of the sheet material and punching execution information as to whether the sheet material is to be punched, wherein the standby position corresponding to a sheet material of the maximum width that can be punched by the punching mechanism and the standby position applied when punching is not executed are set to substantially the same position.
According to a second aspect of the invention, there is provided, in a transported punching system for punching holes in a sheet material comprising a punching mechanism having a plurality of punches disposed on a transport passage of a sheet material in a predetermined spacing in a direction orthogonal to a transport direction of the sheet material for making the punches appear on or disappear from the transport passage, thereby punching a plurality of holes in the sheet material in the predetermined spacing along a width direction of the sheet material, the improvement which comprises first sensing means being disposed on the transport passage of the sheet material positioned between or at the middle of the punches for sensing an end margin in the transport direction of the sheet material transported to the punching mechanism, wherein the punching mechanism is Operated based on sensing information output from the first sensing means, thereby punching a plurality of holes at a predetermined distance from the end margin in the transport direction of the sheet material.
In a third aspect of the invention, the punching system of the first aspect further Includes first sensing means for sensing an end margin in the transport direction of the sheet material transported to the punching mechanism, wherein the punching mechanism is operated based on sensing information output from the first sensing means, thereby punching a plurality of holes at a predetermined distance from the end margin in the transport direction of the sheet material.
In a fourth aspect of the invention, in the punching system as claimed of the second or third aspect, the first sensing means is placed in the substantial center in the width direction of the sheet material.
In a fifth aspect of the invention, in the punching system of the second or third aspect, the first sensing means placed between the center of a sheet material of the maximum width that can be punched and the center of a sheet material of the minimum width that can be punched.
In a sixth aspect of the Invention, the punching system of the first aspect further includes first sensing means being disposed on the transport passage of the sheet material positioned between the punches for sensing an and margin in the transport direction of the sheet material transported to the punching mechanism, wherein the punching mechanism is operated based on sensing information output from the first sensing means, thereby punching a plurality of holes at a predetermined distance from the end margin in the transport direction of the sheet material, and wherein the first sensing means can be moved in the direction orthogonal to the transport direction of the sheet material in conjunction with the punching mechanism.
In a seventh aspect of the invention, in the punching system of the sixth aspect, the first sensing means is placed in the substantial middle of the punches.
In an eighth aspect of the invention, the punching system of any one of the aspects two to seven further includes control means for punching the sheet material so that a distance between the end margin in the transport direction of the sheet material and punch holes becomes constant based on sensing information output from the first sensing means. In a first preferred form, the time interval between the instant at which the first sensing means senses the end margin in the transport direction of the sheet material and the instant at which the punching mechanism starts punching is made constant.
In a second preferred form, the sheet material transport means is driven by a stepping motor and the number of pulses at the time interval between the instant at which the first sensing means senses the end margin in the transport direction of the sheet material and the instant at which the punching mechanism starts punching is made constant.
In a third preferred form, rotation angle sensing means for sensing the rotation angle of the sheet material transport means is provided and the rotation angle of the sheet material transport means at the time interval between the instant at which the first sensing means senses the end margin in the transport direction of the sheet material and the instant at which the punching mechanism starts punching is made constant.
In a fourth preferred embodiment, drive of the sheet material transport means is stopped after the expiration of a given time since the first sensing means sensed the end margin in the transport direction of the sheet material, thereby once stopping the sheet material and punching it in the stop state.
In a fifth preferred embodiment, the sheet material transport means is driven by a stepping motor and is stopped after a given number of pulses are output since the first sensing means sensed the end margin in the transport direction of the sheet material, thereby once stopping the sheet material and punching it in the stop state.
In a sixth preferred form, rotation angle sensing means for sensing the rotation angle of the sheet material transport means is provided and drive of the sheet material transport means is stopped after the sheet material transport means is rotated by a given rotation angle since the first sensing means sensed the end margin in the transport direction of the sheet material, thereby once stopping the sheet material and punching it in the stop state.
In a ninth aspect of the invention, in the punching system of the eighth aspect, the distance between the end margin in the transport direction of the sheet material and punch holes can be changed by changing a parameter containing any of a time interval between the instant at which the first sensing means senses the end margin in the transport direction of the sheet material and the instant at which punching in started, the number of pulses when a step motor is used to transport the sheet material, or a rotation angle of a transport shaft for transporting the sheet material in order to make the distance constant.
In a tenth aspect of the invention, the punching system of the ninth aspect further includes means for inputting distance data between the end margin in the transport direction of the sheet material and punch holes and operation means for converting the distance data input through the input means into the parameter of any of the time, the number of pulses, or the rotation angle, wherein based on the parameter of any of the time, the number of pulses, or the rotation angle, punching is started or sheet material transport means is stopped after the end margin in the transport direction of the sheet material is sensed.
According to an eleventh aspect of the invention, there is provided a punching system for punching holes in a sheet material transported comprising a punching mechanism having a plurality of punches disposed on a transport passage of a sheet material in a predetermined spacing in a width direction orthogonal to a transport direction of the sheet material for making the punches appear on or disappear from the transport passage, thereby punching a plurality of holes in the sheet material in the predetermined spacing along the width direction of the sheet material and means for moving the punching mechanism in the direction orthogonal to the transport direction of the sheet material, at least one second sensing means being disposed in the punching mechanism for sensing an and margin in the width direction of the sheet material at a predetermined distance in the width direction from the middle position of the punches, and means for moving the punching mechanism in the width direction, wherein the punching mechanism moved by the move means is stopped based on sensing information of the second sensing means for punching the sheet material transported to the punching mechanism.
In a twelfth aspect of the invention, in the punching system of the eleventh aspect, the punching mechanism has a plurality of predetermined standby positions where the punching mechanism is previously moved by the move means and stands by based on size information in the width direction of the sheet material and punching execution information as to whether the sheet material is to be punched, wherein the standby position corresponding to a sheet material of the maximum width that can be punched by the punching mechanism and the standby position applied when punching is not executed are made almost identical.
In a thirteenth aspect of the invention, in the punching system of the eleventh aspect, a plurality of the second sensing means are placed, one of which to use is selected in response to size information in the width direction of the sheet material for sensing the end margin in the width direction of the sheet material, and a move of the punching mechanism is stopped based on sensing information of the selected second sensing means for punching the sheet material under a condition determined for each sheet material.
In a fourteenth aspect of the invention, in the punching system of the eleventh aspect, only one second sensing means is placed and a time interval between the instant at which the second sensing means senses the end margin in the width direction of the sheet material and the instant at which the move means is stopped is determined in response to size information in the width direction of the sheet material for punching the sheet material under a condition determined for each sheet material.
In a fifteenth aspect of the invention, in the punching system of the eleventh aspect, a plurality of the second sensing means are placed and one of the sensing means to use and a time interval between the instant at which the second sensing means senses the end margin in the width direction of the sheet material and the instant at which the move means is stopped are determined in response to size information in the width direction of the sheet material for punching the sheet material under a condition determined for each sheet material.
In a sixteenth aspect of the invention, in the punching system of the fourteenth or fifteenth aspect, the move means is driven by a stepping motor and the number of pulses at a time interval between the instant at which the second sensing means selected among a plurality of the second sensing means or single second sensing means senses the end margin in the width direction of the sheet material and the instant at which the move means is stopped is determined in response to size information in the width direction of the sheet material for punching the sheet material under a condition determined for each sheet material.
In a seventeenth aspect of the invention, the punching system of the fourteenth or fifteenth aspect further includes means for sensing a rotation angle of the move means, wherein the rotation angle of the move means at a time interval between the instant at which the second sensing means selected among a plurality of second sensing means or single second sensing means senses the end margin in the width direction of the sheet material and the instant at which the move means is stopped is determined in response to size information in the width direction of the sheet material for punching the sheet material under a condition determined for each sheet material.
In an eighteenth aspect of the invention, in the punching system as claimed in any of the eleventh to seventeenth aspects, before receiving a first sheet material, the punching mechanism is moved to a standby position responsive to a width size of the sheet material based on size Information in the width direction of the sheet material and punching execution information, a move of the punching mechanism is started at the standby position, the move means is stopped under the determined condition, the sheet material is punched under the condition determined for each sheet material, and the punching mechanism is restored to a predetermined standby position after the punching terminates.
In a nineteenth aspect of the invention, the punching system of the eleventh aspect further includes sheet transport attitude correction means for correcting a transport attitude of the sheet material so that the front end of the sheet material becomes parallel with the direction orthogonal to the transport direction of the sheet material and first sensing means for sensing an end margin in the transport direction of the sheet material, wherein after the transport attitude of the sheet material is corrected by the sheet transport attitude correction means, the end margin in the transport direction of the sheet material is sensed by the first sensing means and the sheet material is punched.
In a twentieth aspect of the invention, the punching system of the eleventh aspect further includes second sensing means for sensing an end margin in the width direction of the sheet material transported to the punching mechanism, wherein time at which the second sensing means starts to sense is changed in response to size information of the sheet material.
In a twenty first aspect of the invention as claimed, the punching system of the eleventh aspect further includes second sensing means for sensing an end margin in the width direction of the sheet material transported to the punching mechanism, wherein if the second sensing means does not sense the end margin in the width direction of the sheet material within a given time after the second sensing means starts to sense the end margin in the width direction of the sheet material, the sheet material is not punched.
In a twenty second aspect of the invention, the punching system of the first or twelfth aspect further includes third sensing means for at least sensing a standby position corresponding to a sheet material of the maximum width that can be punched, wherein if the third sensing means does not sense the punching mechanism, punching is inhibited and a mode in which the sheet material passes through the transport passage of the punching mechanism is also inhibited.
The above and other objects and features of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings.